JPS61128409A - Dielectric ceramic composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dielectric ceramic composition characterized by having a high dielectric constant of 8000 or more and a low sintering temperature of 900 to 1000 t:.

(Conventional technology) Multilayer ceramic capacitors are small and large in size;
It has characteristics such as excellent high frequency characteristics, excellent heat resistance, and ease of mass production. Therefore, the demand for it has been increasing in recent years because it meets the demands of industrial electronic equipment and consumer electronic equipment such as lightness, thinness, compactness, high quality, and high frequency design.

Conventional multilayer ceramic capacitors use internal electrodes and CA
It was common to use expensive noble metals such as u, Pt, and Pa.

(Problem to be solved by the invention) However, in the above-mentioned multilayer ceramic capacitor with a small amount of precious metal inside, the majority of the production cost is the cost of the box material, so there is a limit to the total reduction of the overall cost. .

For this reason, oxides such as boron, bismuth, lead, etc. are used in high-d electric conductivity porcelain compositions made of raw barium titanate.
By adding a glass component, the firing temperature was increased from 1300 to
A multilayer ceramic capacitor capable of low-temperature curing has been developed, which lowers the temperature from 1550t to 1100-1150C and uses a relatively inexpensive silver-palladium alloy as the internal electrode.However, a glass component is added. Therefore, the dielectric constant originally possessed by the barium titanate matrix composition is reduced, and when the dimensions of the multilayer ceramic capacitor are changed, C becomes large, which cancels out the reduction in the cost of the electrically conductive material. It was done.

(Object of the invention) However, C1 This invention is similar to the above-mentioned prior art.
, [without causing a decrease in the dielectric constant, that is, the dielectric constant value is 8000 or more, and the sintering temperature is 900 to 10
It is an object of the present invention to provide a dielectric ceramic composition with a low C1
An object of the present invention is to provide a 21-dielectric ceramic composition that can be used as a dielectric material constituting a multilayer ceramic capacitor having a comparatively stable silver-palladium alloy as an internal electrode.

(Structure of the Invention) The dielectric ceramic composition according to the present invention includes Pb(1)Pb
(Ni1/3Nbx, 4)O,, FD'riO,, Pb
(ZraL-W4)O, O and A(Cu4(Nb%)O
, is the main component.

Further, the dielectric ceramic composition useful in the present invention is one in which C manganese is added as a C1 subcomponent to the above-mentioned main component.

The main components mentioned above consist of the following compositional regions.

That is, PI) (Ni conductor NbzA)0. 45-75 Soluchi PbTL0. 20-40 moltiP
Mol Zn4W%)Os ・15~15 Molti A(Cu'4Nbz4)o, 1.0~I Q
It is 9g, KC, and (Cu%Nbt4)O, is Ba and Sr.

and Ca.

Further, the amount of manganese added to the above-mentioned main component as a C1 subcomponent is within the range of Cα5 molti in terms of MnO.

Among the above-mentioned components, the composition range of the main components was limited. The reason for rN is as follows.

1st K1Pb (Ni electric It) ≠ p, when the temperature becomes 45 molar, the dielectric constant becomes less than 8000, and
The dielectric loss tangent exceeds 2.5 t. On the other hand, when 75 momoles are added, the dielectric constant decreases significantly.

It becomes ungrooved.

When M2 is less than Cl2o, the dielectric constant of Pl)TiOs decreases significantly, which is less than 5ooo. On the other hand, when 40 moles are increased by 4, the dielectric constant becomes less than 8000 and the dielectric loss tangent exceeds 2.5.

Third, Pb(Zn%W'()OsKQ, 5%
When it becomes loose, the firing temperature exceeds 1000"C and the dielectric constant becomes less than 8000. On the other hand, 1°5-r: ruti"
As the temperature increases, the firing temperature drops to below 900C, but the dielectric constant becomes 8000, and the resistivity also decreases to 1o11 at room temperature.
Ω, no longer reaches -1. 'Fourthly, MU (Cu% N I)! /” )'s K
When the Li'C%t is less than O morch, the firing temperature is 10%
01t-"4 get.

On the other hand, when the molar ratio exceeds 10, the dielectric constant decreases to less than 8,000 and the resistivity does not reach 10''Q-cm.

In addition, if the amount of manganese relative to the main component exceeds ゛C005 molar equivalent in terms of MnotK, the specific resistance at room temperature will be 1014
Ω, it won't reach Umugi.

(Effects) The dielectric ceramic composition according to the present invention has the following effects.

■ Exhibits a dielectric constant (g) of 8000 or more.

■ The dielectric loss tangent (t4nδ) is less than or equal to ZSLs.

■ Specific resistance is 10"n,m or more at room temperature.

■Sintering temperature is low at 900-100C1'.

(2) By incorporating manganese, the specific resistance at room temperature and high temperature (ast') is improved by more than 10'Ω.

Therefore, the dielectric ceramic composition according to the present invention can be used as a dielectric material not only for general magnetic 3 capacitors but also for multilayer ceramic capacitors. In particular, when manufacturing multilayer ceramic capacitors, due to the low sintering temperature, silver-palladium materials can be used for the inside of C1 and Ef, making it possible to industrially produce small-sized, large-capacity capacitors. be able to.

(Implementation sequence) This invention will be described in detail below according to examples.
, cuo, and MnO were used as starting materials, and each raw material was weighed so as to finally obtain a ceramic composition having the composition ratio shown in Table 1. 100 g of each raw material was weighed, placed in a polyethylene pot together with agate boulders, and mixed for 10 hours. The mixed cast slurry was dehydrated, dried, placed in an alumina box, held at 650-800C for 2 hours, and calcined at -
A next reaction powder (calcined powder) was obtained. The calcined powder was coarsely pulverized in advance, 3 ffit% of polyvinyl alcohol was added as a binder, and wet mixing and pulverization was performed again. After drying the resulting slurry, it was passed through a 50 mesh sieve.
C was made into a sized powder for molding. Next, use an oil press for 20
It was molded into a disk shape with a diameter of 124 mm and a thickness of 1.28 mm at a pressure of 00 hF/d. The molded disk was placed in a zirconia box, set to an appropriate lead atmosphere, and heated to 850 to 11
It was baked at a temperature of 00 r for 2 hours.

A silver paste containing a lead borosilicate glass frit was applied on both sides of the obtained porcelain disk, and baked at 750C for 10 minutes to form a C ring, which was used as a sample for measurement.

For each sample, capacitance (C), dielectric loss tangent (t, nδ)
Use YHI'fi LCR meter 4274.
5c.

Measured at 1KHz and 17rms. In addition, insulation resistance (
(R) was measured using a megohmmeter TR8601 manufactured by Takeda Riken, and the value was measured 2 minutes after direct Rso□v application.

The thickness of the sample and the diameter of the bottom ball were measured, and the dielectric constant (ε) and specific resistance (p) were calculated, and the results are shown in Table 2.

Furthermore, the firing temperatures for each group X are shown in Table 2.

It should be noted that those marked with the middle east part of Table 1 and Table 2 are outside the scope of this invention, and the others are within the scope of this invention.

Claims (2)

[Claims] (1) Pb(Ni_1_/_3Nb_2_/_3)O_
3, PbTiO_3, Pb(Zn_1_/_2W_1_
/_2) O_3 and A(Cu_1_/_3Nb_2_
/_3) A dielectric ceramic composition comprising O_3, each having a molar fraction within the following range. Pb(Ni_1_/_3Nb_2_/_3)O_3 4
5-75 mol% PbTiO_3 20-40 mol% Pb(Zn_1_/_2W_1_/_2)O_3 0.
5 to 15 mol% A (Cu_1_/_3Nb_2_/_3
)O_3 1.0 to 10 mol% However, A(Cu_1_
/_3Nb_2_/_3) A in O_3 is one of Ba, Sr, and Ca. (2) Said Pb (Ni_1_/_3Nb_2_/_3)
O_3, PbTiO_3, Pb(Zn_1_/_2W_
1_/_2) O_3 and A(Cu_1_/_2Nb_
1_/_2) The dielectric ceramic composition according to claim (1), which contains 0.5 mol% or less of manganese in terms of MnO_2 with respect to the main component consisting of O_3. .